Piston ring



T. E. MCFALL PISTON RING April 13, 1948.l

2 sheets-sheet .1'

Filed July 22, 1946 uvm m m PM N Ec o, Wm ,n w M L n. vHV.. TB

Patented Apr. 13, 1948 oFEicE `PISTON RING Thurlow E. McFall, Sparta, Mich. Application July 22, 1946, Serial No. l685,471` v Y l 2 Claims. (Cl. 309-45) This invention relates to piston rings and has for its primary object and purpose the production of a novel, all-steel piston ring to be used in the lower oil groove or grooves of a piston in an internal combustion engine, the ends of theV ring at the parting having an abutting engagement and the ring being circumferentially compressed and shortened in length when it is installed on a piston and within a cylinder. More specifically, the ring includes a continuous spring member which in circular form may be compressed, and a'. plurality of cylinder Wall engaging or scraping elements, separate from each other and separately produced and assembled with the spring member, whereby the tension of the ring may be designed with reference solely to the spring member used, and the oil scraping and collecting members of the ring be of any required dimensions for the most effective wall surface engagement without reference to the strength of the spring used, distinguishingfrom all-steel rings made from a single piece of metal in which, in general, v

either the oil scraping members are too narrow and therefore wear too fast in service, or the spring portion thereof is too heavy and provides too great a pressure against the cylinder wall surface with a danger of scoring or otherwise damaging the cylinder walls; while of course an exceedingly high unit pressure is produced with the result that the ring has a short life of service.

My invention, in a practical, novel and economical manner, obviates such disadvantages and provides a ring of required life of service, having high oil conserving functions.

An understanding of the invention may be had from the following description, taken in connection with the accompanying drawings, in which,

Fig. 1 is a perspective view of a portion of the piston ring made in accordance with my invention, and with the outline of the complete ring diagrammatically shown. A

Fig. 2 is an enlarged fragmentary perspective view of the piston ring at one end or the parting thereof.

Fig. 3 is a similar view looking at the inner or back side of the ring.

Fig. 4 is a fragmentary front elevation.

Fig. 5 is a fragmentary horizontal section through the ring at the parting.

Fig. 6 is a fragmentary elevation of the spring member used, prior to its loop formation.

Fig. 7 is a plan of the blank of the Wall engaging members of the ring, a plurality of which are used with each ring.

Fig. 8 is a fragmentary plan view of the ring I showing the wall engaging members in another form, wherein their upper and lower radial lines or separation are staggered.

Fig. 9 is a front elevation thereof.

. Fig. 10 is a fragmentary horizontal section through a slightly modified construction of the ring.

Fig. 1l is a similar view of a still further modified form, ,and

Fig. 12 is a fragmentary front elevation showing the ring with a modified form of spring structure.

Like reference numbers refer t0 the different figures of the drawings. The wall engaging members, as shown in Figs. 1 to vi inclusive, are each made from a blank of metal having a central section l, from opposite sides of which wider wings 2 identical in shape extend, the central portion I having an opening 3 therethrough. Each of said Wall engaging members of the ring is bent and formed into substantially U-shape, with the central sections I disposed vertically and the wings 2 bent at right angles therefrom in the same direction to provide upper and lower spaced apart wall .engaging flanges., The edges of said flanges are of arc shape to conform `to the inner curved surface of the cylinder wall of an internal combustion engine in which the ring is installed; andthe side edges are on radii extending to the center of the installed ring.

The spring member on which the wall engaging members :are carried is formed from a length of iiat spring material (Fig.;6) inv which there are a pluralityof sections 4 of the full width ofthe band .of spring metal used, and each of which preferably has a `centrally disposedfopening 5 therethrough. From each end of each section 4 a section 6 extends, narrower in width than said sections d, the metal being removed at both upper andV lower edges in each section 6. Any two sections` 6 extending from adjacent ends of successive sections 4 are integrally connected` with opposite ends of an intervening section 1, shorter in length than the sections 4 but having the same width. `Said spring member at each end terminates in la halfl section la, so `that when the two ends at the Vparting of the ring are brought together (Fig. 5), the adjacent vertical edges of the parts la are brought nearly together.

Said band of spring material is shaped and formed into a continuous series of alternate loops as shown in Fig. 5, the sections 1 each being at the forward sides of the forwardly extending loops and the sections 4 at the rear of the rear-- like parts in wardly extending loops, with sections 6 curving toward each other. The loops consisting of the parts 4 and 6 receive the wall engaging members, the parts I being pressed between the adjacent sections 6 and gripped in the bends at the ends of the longer sections 4, with the openings 3 and 5 in substantially radial alinement. The wings or flanges 2 bridge across the sections 6 at both the upper and lower edges, thus providing oil passing slots in addition `to thel 'oil' passing 'open-4 ings 3 and`5.

The assembled spring member and -wall engaging members, as shown in Figs. 2 and 3, provide a piston ring which is contractable circumier entially to smaller diameter by a shortening of the spring member which bends the loopstward each other and which may bring theadjacent edges of the legs or flangesV 2' closery together so that when held within the confines ofa cyl'- inder fwall, substantiallyupper and lower bearing struts between said upper and lowerlanges preventing their distortion.V

In Figs. l to 7` inclusi ve"the ,flanges 2 extend from the intermediate portion I in t'he 'same direction and the edges` aralocated.,one directly over the other.. InFigS. 85 andi) lthe..me1nbers which supply the iiang'es '.to bear against, the cylinder wall are offset laterally "in opposite `directionsfromthe vertical portions I', the' upper flange having, a lateral1y` offset portion to the left. and the lower ange to theright as shown in Figs. 8 and 9'.. The portionsof' vtheslpring' between the sections 4' aremodiied to Yprovide two sectionsawhich takethe places of the At'wo parts I.r and 6d being'narrowed' at'its lower edge and the other at its'upper edge. This staggers the joints betweenthe upper and lower flanges 2a insteadv off being directly overfeach, other.

In F'ig, 10 the structure is substantially the same Yas shown in 1igs.,1` to. 7 .inc'iusive,. being changed in that the gripping portions 4a instead o f being curved as shown in Fig. 5 'are vflattened to lie'against the inner sides of the' vertical parts I of the cylinder wall` bearing members.

`lin 1 1, vinstead of passing 'around and gripping said portions I, `the sections 4b between the sectionsj are shortened inlengthand attened to bear against the outer sides of'thie'pa'rts I Yand are permanentlyY secured thereto. Such permanent connection may be by ,rivetingwelding or vany other equivalent workable form of connection.. v

In Fig. 1 2, Vthe width: of Vthe s pringmember is narrowedand ofthe same y'vic ith' 'forU its entire length, the loops I'bbeing'sh'ort at .both their upperand lowe'redges frointheadjac'ent sides ofA the flanges 2 the ring vfor oilpassage, but' removes' 'the support for the bearing flanges 2' which' however, when made. oi sufficiently sturdyY material'will-'not normally spring or. bend'toward each other so asta-take a permanent set.

with the invention as described, nie tension of IAclrnI 12A piston 'ring' Vstructure comprising, a? spring This provides" ful-l venting`V for"y the ring when in use, and the pressure of the flange edges against the cylinder wall is governed solely by the strength of the continuous spring member, the thickness and width of which may be Varied without reference to the thickness dimension of the wall bearing anges 2 and 2a. Such wall bearing iianges and the vertical members I between them may be made of any desired thickness. The bearing area needed "against the cylinder wall'is obtained without unduly 'or inany way 'effecting' the spring tension against the cylinder Wall, as is the case of" al1 steel piston rings contractable circumie'rentially when made of a single piece `of material. v4Also the material of the spring member "and-"ofthe wall bearing members may be of' a-. diierentcomposition and different properties.

This 'obviate'sthe great wear which occurs because any, attempt to increase the bearing surface requires that the strength;I of the spring must rloe increased; While. a, redaction-Qi .the strength of the ,Springville erre'SDQndinelrreduc-e the bear-1 img areaag'ainst thewalls in theorie-piece rings.`

'Therme-.is Parti-111mg @maestri 0.11 90nservation, readily manufactured, assembled and installed and economic'altoprodu-ce.

and isfto l bei cons'ir'iefi'ed comprehensive of all formsof structure coming 'within their scope.

member cofn'si'sti'ngfofa. singlell'ength off'thin fia@ spring," material, -havieglelieflnsie inwardly and'` outwardly ,extending curved. loops, with adjacent' sid'es'g'of 'the outwardlygeitending'loops in closer'gproiimity to each other than 'the sides of yQeXtendngloopsQ`said Spring member apel' ofsubstantially circular'- outline eo'f in close proxirfnty to each 'lity' f Ci"lnder, wall' engaging each' of fthe inwardlSl e'i'it'ending id ,fcyllnder engaging rr'r'iernliers ing" "ariy interniediate' ye'rtioalf section of fiat inet'al. having' 'iibst'antially i/ert'ica'l edges and ing, overfa'ndat'tljie r 'ou'te'ii edges ajpistorrringg 'apstiring member 'disposed in' 's antially-v rciil'ar' "forni andhaving altersaid Vertical fatel sections' extending througn'said 1 extendingloops with the nan'gesextendlhg outwardly oyerj andA underi n'eath' said outwardlyextendingloops;

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